Hydraulic drill column



May 23, 1939. A.-R. LAWRENCE HYDRAULIC DRILL COLUMN Filed Nov. 24, 19366PINVENTOR ATTORNEY Patented May 23, 1939 UNITED STATES PATENT OFFICECanada Application November .24, 1936, Serial No. 112,506

6 Claims.

This invention relates to a column adapted to serve as a support for adrill, and particularly to such a column which may :be adjusted readilyand when adjusted will aiiord a secure support.

The standard practice in rock drilling with mounted :dr-ills includesthe use of acolum-n serv ing as a support 'for a cross-arm which isadjustable to any height. The drill machine is held rigid on thecross-arm by means of a clamp. The columns vary in length according tothe size of the opening which is being drilled in the rock face. Usuallythe length is about six feet. Such columns are made generally from apiece of three-inch pipe which is titted with a packscrew for tighteningthe column against the floor and roof of the opening close to theworking face of the rock. Such columns are subject to numerousdisadvantages. It is diflicul't to secure enough pressure by means ofthe jack-screw to ensure security, that is to say, to avoid possible thedrill machine 20 loosening of the column while is in operation. Thevibration to which the column is subjected frequently loosens the.iackscrew, creating a dangerous condition unless the looseness ispromptly rectified. Constant attention to the jack-screw is necessary toavoid such danger.

It is the object of the present invention to atford a column of simpleconstruction which permits the application of much greater pressure thanis otherwise possible and which automatically will take up any loosenessand maintain su-fficient pressure to ensure security of the column andof the operations conducted therewith.

Another object of the invention is the provision of a column which maybe readily removed from any position in which it is being operated forreadjustment in another position where the drill is to be used.

Other objects and advantages of the invention will be apparent as it isbetter understood by reference to the following specification and theaccompanying drawing, in which:

Fig. 1 is an elevation in section of a column embodying the invention;

2 is an enlarged sectional view of a portion of the head of the column;

Fig. 3 is a plan view of the head of the column; and

. Fig. 4 is a section on the line 4-4 of 1.

In carrying out the invention, I provide :a column which may, ifdesired, be constructed of :pipe similar to that used in columnsheretofore, that is to say, three-inch iron pipe having an outside 15:;diameter of three and one inches. .Any

suitable tubing having the requisite strength may, however, be employed.I he pipe or tubing is provided with a foot of any suitable materialsuch as cast steel, and embodies at its base a cylinder and pistonadapted to be actuated by pneumatic pressure, for example air at apressure of about 85 pounds per square inch, as normally supplied inmine Work. The piston carries a piston rod operating through a gland,and under the action of the air pressure, when applied, the piston rodis advanced into a chamber which is filled with a hydraulic medium,preferably oil. In displacing the oil, the piston rod causes a plungerto advance, carrying with it a suitable head which is adapted to engagethe roof of the tunnel or stope in which the column is used. When theplunger has advanced as far as possible in consequence of a singlemovement of the .piston rod, a nut carried by the plunger is moved intoengagement with the shoulder to prevent retraction of the plunger. Thehead includes a reservoir for the hydraulic medium such as oil, and whenthe piston rod is retracted under the influence of a spring provided forthat purpose, the hydraulic medium flows from the reservoir into theinterior of the plunger in an amount equivalent to that displaced by thepiston rod.

When air is again admitted to the cylinder at the base of the column,the valve leading to the reservoir is closed, and displacement of thehydraulic medium, as the piston rod rises again, causes the plunger andhead to advance. Repeated operations cause the head to engage with theroof of the tunnel or stope under the relatively enormous pressuredeveloped, the pressure being maintained by retaining pneumatic pressurein the cylinder at the base of the column, so that if any loosenessdevelops it is immediately taken up by corresponding movement of theplunger.

A by-pass is provided between the reservoir in the head of the columnand the interior of the plunger, and is controlled by a suitable valve,preferably a simple screw device. When the column is to be released, thenut is moved backwardly from the shoulder with which it is engaged, thevalve is opened manually, and the pneumatic pressure is released. Theplunger will sink as the hydraulic medium moves upwardly through theby-pass into the reservoir. The valve controlling the by-pass is thenagain closed, and the column is ready for use again in its new position.

With this preliminary description of the structure and its function,reference is made to the drawing, in which 5 indicates the body of thecolumn consisting of any metal tubing having the necessary strength. Afoot 6 of cast steel or similar material is threadedly secured to thebase of the column 5 and is securely held thereto by a screw 1. Althoughthe tubular body 5 may be machined internally to a smooth finish, Iprefer to employ sleeves 8 and 9 of brass or other suitable materialconnected by a bushing I0, including a gland which consists of packingII, a packing ring I2 andnuts l3.

In the lower cylinder afi'orded by the sleeve 8,

I provide a piston |4 having a cup I5 of leather or other suitablematerial secured by a washer l6 and nuts I1. A retractile spring I 8 issecured to the lower side of the piston and to the bottom of the foot 6so that the piston is normally disposed at the lower end of thecylinder. The nipple I9 is adapted to be connected by a hose to thesource of pneumatic pressure normally maintained in the mine, suitablevalves being provided to control the introduction and release of thepneumatic pressure. A so-called three-Way valve (not shown) is usuallyemployed for this purpose, permitting the introduction of the pneumaticmedium to the cylinder and the release of this medium as may be desired.

A piston rod 20 is connected to the piston l4 and extends through thegland in the bushing l into the interior of the upper chamber formed bythe sleeve 9. In this chamber a hollow plunger 2| is provided with a cup22 of leather or other suitable material secured to its lower end so asto aiford a tight fit. Movement of the plunger is limited by engagementof a shoulder 23 with the lower edge of a ring 24 which. is held by ascrew 25 at the upper end of the sleeve 9. The plunger is provided nearits upper end with a heavy thread 26 and a nut 21, the size of thethread being such that the nut can be turned manually. The nut 21 isadapted to be brought into engagement with a shoulder 28 at the upperend of the column after the plunger has been moved up by the operationof the piston rod 20 as hereinafter de scribed.

The interior of the plunger 2| and the space above the bushing H! isfilled with a hydraulic medium, preferably oil. A head 29 of cast steelor other suitable material is threadedly secured to the upper end of theplunger 2| and is held against movement relative thereto by a screw 30.The head includes a reservoir 3| for the hydraulic medium which isadapted to drain through an opening 32 into the interior of the hollowplunger 2| under control of a valve 33 having passages 34 therethrough.The valve is normally held against the conical seat 35 by a spring 36resting on a shoulder 31. During the upward movement of the plunger 2|,the valve remains closed and is held closely against the seat by thepressure of the hydraulic medium beneath the valve. A bypass 38 extendsfrom the reservoir 3| to a point beneath the valve 33 and is controlledby a valve consisting of a manually operable screw 39. This valve isopened only when the column is to be released to permit the flow of thehydraulic medium upwardly into the reservoir. A filling plug 40 with anair vent 4| is provided in the top of the reservoir to permit theintroduction of the hydraulic medium and to afford connection with theatmosphere, so that the hydraulic medium may flow from and to thereservoir during the operation of the device.

Such operation should be readily apparent from the foregoingdescription. When the column is to be used, it is set up in the desiredposition and connected to the source of air pressure. Air is permittedto enter the lower cylinder, thus advancing the piston rod 20 anddisplacing the hydraulic medium within the plunger 2|. This causes theplunger to move upwardly, the valve 33 being closed at this phase of theoperation, as indicated in Fig. 2. When the piston M has reached theupper limit of its travel, the nut 21 is moved downwardly intoengagement with the shoulder 28, thus preventing retraction of theplunger. The pneumatic pressure is then released, and the piston I4 isretracted by means of the spring |8. The withdrawal of the piston rod20' results in reduced pressure within the plunger 2|, and the valve 33opens to the position indicated in Fig. 1, so that the hydraulic mediumis permitted to flow from the reservoir into the hollow plunger in anamount equivalent to the displacement of the piston rod 20. Pneumaticpressure is again applied, forcing the piston l4 upwardly, the valve 33being again closed as in Fig. 2, and the plunger 2| is again advanced.The operation may be repeated until such time as the head 29 is firmlyin engagement with the roof and sufficient pressure is afforded so as tomaintain the column in its desired position.

With the apparatus as described, it is possible to multiply theavailable pneumatic pressure, usually of about 85 pounds per squareinch, into an efiec'tive pressure of 4,000 pounds or more per squareinch, thus ensuring rigidity of the column. It will be noted, moreover,that while the column is in use, the pneumatic pressure is maintained,and consequently if there is any tendency to loosen, the plunger 2| isimmediately forced upwardly, so as to continuously maintain the desiredpressure against the roof of the tunnel or stope.

When the column is to be released, the nut 21 is first moved backwardlyto the position indicated in Fig. 1, and the valve 39 is opened so as topermit the hydraulic medium to flow backwardly into the reservoir. Thepneumatic pressure is then released, and the plunger 2| sinks to itslowermost position, displacing the hydraulic medium which returns to thereservoir. The valve 39 may then be closed and the column is ready foruse in its new position.

When the column is in position, the drilling machine indicated generallyin dotted lines as 42 may be secured to the usual cross-arm (not shown).The details of the cross-arm and clamp and of the drilling machine formno part of the present invention. Such devices are well known in theart, and those adapted for use with columns as heretofore known may beused similarly with the improved hydraulic column as herein described. 5

Among the particular advantages of the invention are greater rigidity,security and safety, and greater facility in setting up and taking downthe column, with consequent reduction in the labor and energy requiredin the operation of the drilling machine. The column as described, whichemploys principles of both pneumatic and hydraulic mechanisms, avoidsthe disadvantages of apparatus in which attempts have been made to useeither of these principles separately. The improved column is adaptedfor practical mine conditions and has been successfully used for itsintended purpose without any necessity for supplemental and unusualequipment which is not ordinarily available in mine operation.

Various changes may be made in the details of construction andarrangement of the parts of the apparatus without modifying theinvention or sacrificing any of the advantages thereof.

I claim:

1. A portable column for supporting a drilling device comprising acylinder having an unobstructed exterior portion of substantial lengthalong which the mounting of a drilling machine may slide, a plungermovable therein, a member extending across said cylinder and at least inpart movable longitudinally thereof, a hydraulic medium within saidcylinder at one side of said member, means for admitting fluid to theside of said member opposite the hydraulic medium for moving at least apart of said member longitudinally of the cylinder in one direction,

said member substantially preventing flow of the actuating mediumtherepast, reciprocation of said member causing a displacement of atleast a portion of the hydraulic medium and an advancement of theplunger, means for holding the plunger in its advanced position, areservoir for hydraulic medium formed within the column, and meansactuated by return movement of said member for supplying hydraulicmedium from said reservoir to the cylinder.

2. A portable column for supporting drilling devices comprisingseparated cylinders, a piston in one cylinder having a rod projectinginto the second, a plunger in the second cylinder, liquid means in thesecond cylinder adapted to be displaced by the rod whereby the plungeris advanced, adjustable means to limit return movement of the plunger,reservoir means carried by the plunger from which additional liquid issupplied to the second cylinder when the rod is withdrawn, and valvemeans controlling the flow of liquid to and from the reservoir, saidvalve means being actuated to open position by the withdrawal of the rodfrom said second cylinder.

3. A column for supporting drilling devices comprising separatedcylinders, a piston in one Y cylinder having a rod projecting into thesecond,

second cylinder when the rod is withdrawn.

4. A column for supporting drilling devices comprising separatedcylinders, a piston in one cylinder having a rod projecting into thesecond, a plunger in the second cylinder, liquid means in the secondcylinder adapted to be displaced by the rod whereby the plunger isadvanced, adjustable means to limit return movement of the plunger,reservoir means independent of the first cylinder consisting of a hollowhead secured to the plunger to supply additional liquid to the secondcylinder when the rod is withdrawn, and valve means controlling the flowof liquid to and from the reservoir.

5. A portable column for supporting a drilling device comprising acylinder having an unobstructed exterior portion of substantial lengthalong which the mounting of a drilling machine may slide, a plungermovable therein, an hydraulic medium within said cylinder, pneumaticallyactuated means for displacing the hydraulic medium and thereby advancingthe plunger, means for holding the plunger in its advanced position, areservoir for a supply of additional hydraulic medium, a conduit forsupplying hydraulic medium from said reservoir to the hydrauliccylinder, when the displacing means is withdrawn, a by-pass around saidconduit from said reservoir to the hydraulic cylinder, and valve meansfor controlling passage of the hydraulic medium through said by-pass.

6. A portable column for supporting a drilling device comprising acylinder having an unobstructed exterior portion of substantial lengthalong which the mounting of a drilling machine may slide, a plungermovable therein, an hydraulic medium within said cylinder, pneumaticallyactuated means for displacing the hydraulic medium and thereby advancingthe plunger in its advanced position, a reservoir for a supply ofadditional hydraulic medium, a conduit for supplying hydraulic mediumfrom said reservoir to the hydraulic cylinder, a valve normallypreventing the flow of hydraulic medium through said conduit, said valvebeing actuated to open position by withdrawal of the displacing means, aby-pass around said conduit from said reservoir to the hydrauliccylinder, and valve means for controlling passage of the hydraulicmedium through said by-pass.

ARCHIBALD R. LAWRENCE.

